The present invention relates to the general field of dispensers for thermoplastic products, such as depilatory wax, salves, creams, and possibly even glues or varnishes, in which the product must be in a softened or liquid state in order to be applied, is normally stored in a solid form, and must be heated in order to be changed into a softened or liquid state.
The present invention more specifically concerns a dispenser for thermoplastic products, and in particular depilatory wax, which dispenser includes a case or housing equipped with a holding element, a reservoir for the product to be applied, which reservoir is in thermal communication with heating means, and at least one means, disposed in front of an outlet orifice of the reservoir, for applying the product.
As used herein, thermoplastic products include all types of products which are in a solid, semi-solid or highly viscous state at room temperature but which, upon being heated, will be softened or liquified sufficiently to be capable of being spread in the form of a layer. While the invention is particularly directed to a depilatory wax dispenser, it will become apparent that a product dispenser according to the invention is not limited to this specific use.
Regardless of the type of depilatory wax dispenser considered, the technique for removing hair by application of a depilatory wax consists in melting or softening a certain quantity of wax, and then applying the wax, in a liquid or softened state, in the form of a layer over the area to be treated. After the wax hardens, i.e. cools, there exists a film or sheet of cold wax which is pulled away from the treated area, with the aid of any suitable appliance, with strands of hair then being plucked from the skin due to the fact that they are lodged firmly in the wax.
In order to implement this widely used technique, distributors of hot wax ready for use are already known. These distributors are constituted by a reservoir heated by any suitable means, for example by a device analogous to a heater for baby bottles. These distributors are completed by a simple roller for spreading wax which the user introduces into the reservoir in order to form a regular coating of hot wax on the roller. This apparatus, which is rather primitive, has been found to no longer satisfy the increasingly sophisticated needs of users of depilatory wax. In these devices, the temperature to which the wax is heated for application is poorly regulated, as is the thickness of the applied wax layer. These apparatus are also known to be relatively cumbersome and the associated depilatory operation is long, tedious, often messy and frequently involves an excess consumption of wax.
Improvements in prior art devices of this type are described in French Application A-2520601. The dispenser assembly described therein includes a case or housing provided with heating receptacles in which are inserted dispensers that are intended to be held by the user. Each dispenser is provided with an internal reservoir intended to contain a supply of depilatory wax in solid form and with a wax applying roller. Such a dispenser represents an improvement over previous devices, but does not completely resolve the problems associated with proper control of the temperature of the wax at the time it is applied. In effect, if the temperature of the wax is satisfactory when the user initially withdraws the dispenser from the heating receptacle, it will inevitably occur that after a certain period of use, the wax is no longer at a suitable temperature. This leads to an increasing difficulty in applying the wax, a waste of wax and a depilatory operation which is unreliable, uneven and in any case unsatisfactory. In order to obviate these problems, the user is required to frequently return the dispenser to the housing receptacle and this prolongs the duration of the process without any added assurance of achieving an improved result.
In light of these difficulties, it has also been proposed, as disclosed, for example, in European Application A-0368698, to provide a depilatory wax dispenser in which the wax reservoir is provided with a heating resistance. To improve the ease of application of the wax, and also to achieve better temperature control, it has also been proposed to furnish the application roller of the dispenser with its own heating means. Such an arrangement assures a certain control over the temperature of the wax and prevents, in particular, a premature adherence of the wax to the reservoir wall. In the same fashion, the fact of heating the dispenser roller prevents a premature cooling of the wax during its application to the skin. On the other hand, such an arrangement present difficulties in manufacture, to the extent that it requires the presence and the installation of two separate heating means, one of which is difficult to operate and install, since it must be positioned within the application roller. In the final analysis, such a device is not highly reliable.